Anesthesia and analgesia
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Infusion systems are complicated electromechanical systems that are used to deliver anesthetic drugs with moderate precision. Four types of systems are described-gravity feed, in-line piston, peristaltic, and syringe. ⋯ A brief example of the use of an infusion system during anesthetic induction is presented. With understanding of the functioning of these systems, users may develop greater comfort.
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Anesthesia and analgesia · Apr 2018
Randomized Controlled Trial Comparative StudyAddition of Nasal Cannula Can Either Impair or Enhance Preoxygenation With a Bag Valve Mask: A Randomized Crossover Design Study Comparing Oxygen Flow Rates.
A critical safety component of emergency anesthesia is the avoidance of hypoxemia during the apneic phase of a rapid sequence intubation. Preoxygenation with a bag valve mask (BVM) or anesthetic circuit may be improved with supplemental oxygen by nasal cannula (NC) if there is a mask leak. In addition, NC is recommended for apneic oxygenation after induction and may be placed before preoxygenation. However, the optimum NC flow rate for preoxygenation or whether the presence of NC alone creates a mask leak remains unclear. ⋯ Our study found that NC at 0 and 5 lpm with a BVM is deleterious to preoxygenation and should be avoided. In addition, a lack of difference between NC-10 and BVM-only demonstrates that NC at flows of at least 10 lpm should not impair the preoxygenation process. While NC-15 may offer a benefit by reaching maximal ETO2 at 1 minute, this would need to be balanced against patient comfort.
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Anesthesia and analgesia · Apr 2018
Randomized Controlled Trial Comparative StudyUltrasound-Assisted Versus Fluoroscopic-Guided Lumbar Sympathetic Ganglion Block: A Prospective and Randomized Study.
Fluoroscopy (FL)-guided lumbar sympathetic ganglion block (LSGB) is widely performed to diagnose and manage various diseases associated with sympathetically maintained pain. Recently, numerous ultrasound (US)-assisted procedures in pain medicine have been attempted, showing an advantage of low radiation exposure. This randomized, prospective trial compared the procedural outcomes and complications between FL-guided and US-assisted LSGBs. ⋯ US-assisted LSGB appears to be a feasible method with the added benefit of lower radiation exposure. In our study, we did not find an advantage of US-assisted LSGB over FL-guided LSGB in terms of performance time.
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Anesthesia and analgesia · Apr 2018
ReviewThe Science of Local Anesthesia: Basic Research, Clinical Application, and Future Directions.
Local anesthetics have been used clinically for more than a century, but new insights into their mechanisms of action and their interaction with biological systems continue to surprise researchers and clinicians alike. Next to their classic action on voltage-gated sodium channels, local anesthetics interact with calcium, potassium, and hyperpolarization-gated ion channels, ligand-gated channels, and G protein-coupled receptors. They activate numerous downstream pathways in neurons, and affect the structure and function of many types of membranes. ⋯ Allergy to local anesthetics is rare, while the variation in individual patient's response to local anesthetics is probably larger than previously assumed. Several adjuncts are available to prolong sensory block, but these typically also prolong motor block. The 2 main research avenues being followed to improve action of local anesthetics are to prolong duration of block, by slow-release formulations and on-demand release, and to develop compounds and combinations that elicit a nociception-selective blockade.
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Anesthesia and analgesia · Apr 2018
Randomized Controlled TrialHeating and Cooling Rates With an Esophageal Heat Exchange System.
The Esophageal Cooling Device circulates warm or cool water through an esophageal heat exchanger, but warming and cooling efficacy in patients remains unknown. We therefore determined heat exchange rates during warming and cooling. ⋯ Esophageal warming transferred 18 W which is considerably less than the 80 W reported with lower or upper body forced-air covers. However, esophageal warming can be used to supplement surface warming or provide warming in cases not amenable to surface warming. Esophageal cooling transferred more than twice as much heat as warming, consequent to the much larger difference between core and circulating fluid temperature with cooling (29°C) than warming (6°C). Esophageal cooling extracts less heat than endovascular catheters but can be used to supplement catheter-based cooling or possibly replace them in appropriate patients.